The present application relates generally to an improved data processing apparatus and method and more specifically to mechanisms for moving control of storage devices from one adapter pair to another.
A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. SSDs distinguish from traditional hard disk drives (HDDs), which are electromechanical devices containing spinning disks and movable read/write heads. SSDs, in contrast, use microchips that retain data in non-volatile memory chips and contain no moving parts. Compared to traditional HDDs, SSDs are typically less susceptible to physical shock, are quieter, and have lower access time and latency. SSDs use the same interface as hard disk drives, thus easily replacing them in most applications.
SSDs in a traditional disk array present challenges when upgrading a system in order to maximize performance. Because there is such a large disparity in performance capability between mechanical and solid-state devices, a relatively small number of SSDs can fully consume the performance capability of a pair of redundant array of independent disks (RAID) adapters. When upgrading a system to add RAID adapters, HDDs, or SSDs, it is often necessary to move devices from one adapter pair to another. Current art requires that the operation to move devices form one adapter pair to another is non-concurrent. The alternative is to add additional devices and copy the data within the system.